cpdf (CLI tool to manipulate PDF files)

The cpdf command line tool allows you to manipulate existing PDF files
in a variety of ways. For example:

* Merge PDF files together, or split them apart
* Encrypt and decrypt
* Scale, crop and rotate pages
* Read and set document info and metadata
* Copy, add or remove bookmarks
* Put multiple pages on one (imposition)
* Stamp logos, text, dates, page numbers
* Add or remove attachments
* Losslessly compress PDF files
* Convert PDF files to and from JSON

This tool has been available commercially from Coherent Graphics Ltd
since 2007, in 2013 it was released for free under a
not-for-commercial-use license.

This script builds the cpdf command line tool and cpdf as an OCaml
library.
